[mrsD]

You have to see this:


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and here is an explanation:

The silver rings, as it turns out, are "air-core vortex rings", and the helices are a similar phenomenon. Invisible, spinning vortices in the water are generated from the tip of a dolphin's dorsal fin when it is moving rapidly and turning. According to Hans: "Being unstable without a boundary nearby, the vortex line tends to form into a more stable form such as a helix. When the dolphins break the line, the ends are drawn together into closed rings. Owing to the Bernoulli effect, the higher velocity fluid around the core of the vortex is at a lower pressure than the fluid circulating farther away. Air is injected into the rings via bubbles released from the dolphin's blowhole." The energy of the water vortex is enough to keep the bubbles from rising for a reasonably long period--on the order of 10 seconds. There also seems to be a separate mechanism for producing small rings, which a dolphin can accomplish by a quick flip of its head.

There is little doubt that this is what is occurring. However, understanding the physics should not diminish our appreciation of this spontaneous act of creation by a dolphin mind. These young dolphins have detected, understood, and manipulated a subtle aspect of their environment, for no reason other than play.

Creation of these rings by dolphins isn't new. (far from it--dolphins were probably blowing magnificent silver rings while our anscestors were hanging off tree limbs). It does seem to be a relatively rare behavior, though: it has been seen before only in a specific group of dolphins documented by Diana Reiss and Jan Ostman at Marine World. "The fact that ring-blowing is rare and that we have two babies doing it suggests that one baby learned it from the other", comments Ken Marten. "Whether it was a case of observational learning, or one "taught" the other, we don't know... but it'd sure be interesting to know."

The social situation also seems to affect ring-blowing: " The babies made them most intensely when they were the only two dolphins in the tank and when there was only one adult. The behavior stopped entirely when they were outnumbered by adults, " observed Suchi. "During one intense session with Tinkerbell there were often two or three rings visible in the tank at one time. She frequently swam over to me in an excited state, then went and made some more."

I can't link to this paper...it has a generic address! but it was written by Don White, Creator of Project Delphis. (the whole essay is available at

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[Snoopy]

mrsd, thanks for sharing the video - it was truly amazing.